But with Usenet, you don't lose access to any content at all. It would be like if one reddit server bans you, but you can still use reddit and other people can still see your comments because other servers, owned by other people, also host reddit.

Usenet is a loose federation of services handing articles to each other. If one newshost decides that they don't have the money/time to keep the lights on, you can seamlessly use another newshost which will let you fetch and post articles. Likewise if a newshost believes you're not worth the trouble to allow posting, another newshost can let you post. It's very hard to get banned from every newshost. That said, individuals often decide whom to block as many newsreaders allow users to score content and remove content from their local feeds that they feel score low.

If Reddit decides that a certain user or even a certain subreddit shouldn't be a part of Reddit anymore, that user or subreddit is off Reddit. If a news server decides not to accept or relay articles destined for a certain group, chances are high that another newshost _will_ be okay with accepting/relaying those articles.